Speed Sensor Issue?

[imtheengine]

Hi everybody,

I'm new to the forum and back on the road after a 6 month lay-off (broken ankle - football, I know, I've stopped playing!), it didn't take long to get her ('04MY) fit and good to go and the day my tax disc turned up I was out! As ever she was running great but after half an hour suddenly my speed display read zero mph and my trip counter & odometer stopped counting up (clearly as no speed is registered). All other indications are correct and after looking through the "old" forum page I read that this is problem has in the past been accompanied by a flashing Programmable Fuel Injection (PFi) red light, which on my bike is fine. The bike also continued to run fine, this was the only issue. In accordance with the workshop manual I've measured a 5 volt pulse voltage from the speed sensor (at the connector behind the right rear seat cowling) and as a precautionary measure removed the speed sensor to make sure there was nothing obvious.

Can anybody suggest a way ahead? All help greatly appriciated.

Ride safe - ride fast!

[SubSailor]

Did you check speed sensor pulses at the speed sensor connector or at the instrument panel connector?
If not, it would be good to check for pulses at the instrument panel connector in case there is a wiring/corrosion problem.

Do you also have instrument panel illumination along with tail light operation?
If not, then you may have a blown 10A Fuse 'E', which is located in the fuse box behind the left lower cowl, near the coolant overflow bottle.

Also check for corroded electrical contacts during your checks. If the contacts are a bit green due to corrosion, mate/de-mate the connector a few times to create better metal-metal contact, then apply a dab of dielectric grease to the female connector for moisture protection (actually a great thing for all electrical contacts).

[imtheengine]

Hi, thanks for your quick reply - btw, looks like by the title of your username we might be in the same profession deeps!

Anyway...I've checked the speed sensor pulse voltage at both the s/s connector & the intrument panel connector. The voltage is present at both connectors. As a side note, is this voltage constantly greater than 5 volts? When I turn the rear wheel it doesn't appear to fluctuate?

However, I've just this minute checked the instrument panel illumination and the rear light operation. There is the familier "yellow" hew of the intrumentation panel but the tail light is permanantly on, indicating the brakes are on; I've also made sure both brake microswitches are not made so I'll investigate the 10Amp fuse, fuse E.

As soon as I've time I'll get on those connectors too.

Many thanks, I'll let you know how I get on.

[SubSailor]

Some clarification please.
When you measure the speed sensor pulse voltage at the instrument panel connector, are you getting fluctuations as you rotate the rear wheel?
The speed sensor is a magnetic reluctance type and the the output voltage should be a series of square waves (0-5V) which are shown as pulses on a meter.
If you are not detecting pulses but a solid 0V or 5V, then your speed sensor may be bad.